In the latest of a series of government warnings about the consequences of a vote to leave, Mr Osborne shared a stage with his Labour predecessor, Lord Darling, setting out £30bn of “illustrative” tax rises and spending cuts.

These include a 2p rise in the basic rate of income tax and a 3p rise in the higher rate, while they will also say spending on the police, transport and local government could take a 5% cut.

They also said the ring-fenced NHS budget could be “slashed”, along with education, defence and policing.

Mr Osborne and Lord Darling said the measures – £15bn of tax rises and £15bn of cuts – are based on the Institute for Fiscal Studies’ predictions about the economic impact of a vote to leave from lower trade, investment, and tax receipts.

Writing in The Times ahead of their joint appearance, Mr Osborne and Lord Darling say that leaving the EU would lead to a “profound economic shock that would hit the economy and could tip Britain back into recession”.

“We know all too well what happens when Britain loses control of its public finances,” they wrote. “We’re agreed that a vote to leave risks doing the same thing to Britain all over again.”

Mr Osborne told Radio 4’s Today that leaving the EU would be an “irreversible” step that would cause “financial instability” and leave the UK “with no economic plan”, demanding an immediate response from government.

“There would have to be increases in tax and cuts in public spending to fill the black hole,” he said.

The UK, he suggested, would not be able to “afford the size of the public services that we have at the moment” outside the European Union and would have to “cut its cloth accordingly”.

He also played down the threat of Conservative MPs blocking an emergency Budget, suggesting that Labour and Conservative MPs would join forces to “take the necessary measures”.

‘Damascene conversion’

But Labour leader Jeremy Corbyn, whose party is on the same side as Mr Osborne in the referendum debate, said he would not support an emergency budget.

“We would oppose any post-Brexit austerity Budget, just as we have opposed any austerity Budget put forward by this government,” he told David Cameron at Prime Minister’s Questions.

He urged the prime minister to “condemn the opportunism of 57 of your colleagues who are pro-Leave”, who he said had “suddenly” undergone “a Damascene conversion to the anti-austerity movement”.

Mr Cameron said “nobody wants to have an emergency Budget, nobody wants to have cuts in public services, nobody wants to have tax increases,” but he said the economic “crisis” that would follow a vote to leave could not be ignored.

“We can avoid all of this by voting Remain next week,” he told MPs.

In his interview, Mr Osborne ruled out seeking any further concessions from the EU on immigration rules, saying his focus was on implementing restrictions on benefits negotiated by David Cameron earlier this year.

Mr Darling told ITV’s Good Morning Britain that the consequence of a vote to leave the EU would be that “we’ll have less money to spend on things like the NHS or education”.

‘Breaking pledges’

The Conservative government last year introduced legislation not to raise income tax rates, VAT or National Insurance for the duration of the Parliament.

Leave campaigners dismissed the warning from Mr Osborne.

Iain Duncan Smith, Liam Fox and Owen Paterson are among the Conservative MPs who have signed a statement saying they “cannot possibly allow” cuts to services their party promised to protect in their 2015 manifesto.

‘We find it incredible that the chancellor could seriously be threatening to renege on so many manifesto pledges,” they said.

“It is absurd to say that if people vote to take back control from the EU that he would want to punish them in this way.”

They added: “If he were to proceed with these proposals, the chancellor’s position would become untenable.”

‘Shocked’

Conservative MP and Vote Leave campaigner Steve Baker said: “I am shocked that the chancellor is threatening to break so many key manifesto pledges on which all Conservative MPs were elected.”

And a senior Conservative told the BBC it was “laughable” to think Mr Osborne would still be chancellor if the UK voted to leave, adding: “He’ll be carried away by the men in white coats before he gets the chance to make these ludicrous proposals.”

And opposition sources told the BBC that no shadow Labour chancellor “would respond to an economic shock in this manner”.

“Any credible economist would tell you that raising taxes or cutting spending or both in response to an economic shock is the wrong thing to do. It’s deeply worryingly that this suggests the current Tory Chancellor thinks this is a sensible response,” they said.